1. Field of the Invention
This invention pertains generally to a process for production of liquid sugar essentially from brown sugar derived from sugar cane. This invention pertains particularly to a process for production of liquid sugar suitable for use in bottled soft drinks and comparable in color to liquid sugar produced primarily from refined sugar.
2. Brief Description of the Prior Art
It is known to produce liquid sugar, of a type called bottler's liquid sugar herein to reflect its principal utility for use in bottled soft drinks, generally from cane sugar and particularly from a mixture containing a major portion of refined sugar, which has been crystallized from sugar liquor in early strikes, and a minor portion of brown sugar, which has been crystallized from sugar liquor in intermediate strikes. As bottler's liquid sugar may be produced in some countries, particularly where refined sugar is not available in sufficiently large quantities at sufficiently low cost to foster use of refined sugar in pure form, as much as about 10 to 14% by dry weight of brown sugar may be used. Despite its availability commonly in large quantities at low cost, greater amounts of brown sugar have been excluded from production of bottler's liquid sugar, so as to avoid unacceptable discoloration.
Various techniques for decolorization of sugar liquors and sugar syrups have been practiced, in production of refined sugar in refineries, conventionally before crystallization from sugar liquors. Such techniques have employed various carbonaceous materials, ionic-exchange resins, ionic-sorption resins, and various other materials. One technique of particular interest has employed chloride form of Type-1 strong-base anion-exchange resin.
The technique employing chloride form of Type-1 strong-base anion-exchange resin, as applied variously to sugar liquors and sugar syrups, is described in various publications including U.S. Pat. No. 2,785,998 to F. H. Harding et al.; G. Merrill Andrus, "Sugar Decolorization with Anion-Exchange Resins", Reprint from the May 1967 issue of Sugar y Azugar; F. X. McGarvey, "The Evaluation of Ion Exchange Resins for Sugar Liquor Decolorization", Paper presented to Meeting of Sugar Industry Technicians, New York, May 2-4, 1965; and Duolite Ion Exchange Resins in the Treatment of Sugar Solutions,.COPYRGT. 1972 Diamond Shamrock Corporation, particularly at pages 38 through 40.
A detailed description of a typical sequence including decolorization in production of cane sugar by several sequential strikes from sugar liquors is found in Chapters 18 through 20 of Spencer-Meade, Cane Sugar Handbook (9th Edition, John Wiley & Sons, Inc., 1963). It is evident from Spencer-Meade, op. cit., and other sources that sugar refineries are major investments of vast capital, whereupon it is to be expected that increased demand for refined sugar, as for use in bottled soft drinks, cannot easily be accommodated from local refineries in some areas where expansion capital is not readily available for such refineries.